Forward error correction (FEC), known also as channel coding, is one of the key tools that enabled the massive growth of the wireless communications industry in the last decade. The basic role of FEC is to provide the users with reliable digital transmission using minimum excess power, bandwidth and complexity. Consequently, FEC substantially contributed to the success of transformation towards the A5 vision (anyone to access anything from anywhere at any time on any device). Such vision has placed stringent quality of service (QoS) requirements, which require optimal design at all layers of the wireless communications protocol stack to reduce the cost, power consumption and complexity while increasing the capacity, coverage and reliability. Watching high definition television (HDTV) on small-size mobile devices is an example for such extreme QoS requirements because such application requires up to 34 Mbps with packet error rate less than 10−6. The problem becomes even more challenging when such mobile devices are used for transmission. For example, video conferencing requires up to 192 Mbps and packet error rate of less than 10−4.
Turbo Product Codes (TPCs) are currently included in various communication standards such as the IEEE 802.16 for fixed and mobile broadband wireless access systems, which is commercially known as the Worldwide Interoperability for Microwave Access (WiMAX), IEEE 802.20 Mobile Broadband Wireless Access (MBWA) for local and metropolitan area networks, and IEEE-1901 for broadband power line networks. Moreover, TPCs have been proposed for many applications such as optical communications, satellite systems, multimedia transmission and data storage devices.
There are traditionally two types of decoders used for block codes such as TPCs, Hard Decision (HD) decoders and Soft Decision (SD) decoders. As compared to SD decoders, HD decoders have poor performance and low complexity. SD decoders have better performance however they remain highly complex because they use very large number of HD decoders as part of their overall process and system.